Ozone activation over core-shell nanoreactors for enhanced organic pollutants degradation: Surface-bound superoxide radicals induced by confinement effect.

The ubiquity of conventional radical-mediated oxidation pathways in ozone-based advanced oxidation processes (AOPs) fundamentally limits their practical efficacy, particularly in achieving efficient organic degradation while minimizing interference from complex water matrices. To address this challenge, a novel core-shell nanoreactor (FeMn-700) was constructed through controlled pyrolysis of FeMn Prussian blue analogue (PBA) precursors for catalytic ozonation. This architecture creates a confined microenvironment where synergistic interactions between Fe/Mn active sites and reactants enable surface-mediated oxidation mechanisms. The FeMn-700/O system demonstrated exceptional performance, achieving complete removal of phenol (20.0 mg L) within 20.0 min with a remarkable rate constant (k) of 0.66 min. Crucially, the nanoconfinement effect confers superior tolerance to diverse ionic interference and maintains 100.0 % efficiency in real water matrices (lake water, rainwater, sea water, tap water and secondary settling tank water). Mechanistic studies reveal that spatial confinement facilitates reactant enrichment and promotes surface-bound superoxide radical (O) formation, bypassing conventional bulk-phase OH pathways. Toxicity evaluation revealed substantial reduction in ecotoxicity during degradation, confirming effective detoxification. This work provides new insights into the design of confined catalytic systems for water remediation, offering a promising solution to overcome the matrix interference limitations of conventional AOPs.